An enzyme-chromogenic surface plasmon resonance biosensor probe for hydrogen peroxide determination using a modified Trinder's reagent

An absorption-based surface plasmon resonance (SPRAbs) biosensor probe has been developed for simple and reproducible measurements of hydrogen peroxide using a modified Trinder's reagent (a chromogenic reagent). The reagent enabled the determination of the hydrogen peroxide concentration by the development of deep color dyes (λmax = 630 nm) through the oxidative coupling reaction with N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate (MAOS; C13H20NNaO4S·H2O) and 4-aminoantipyrine (4-AA) in the presence of hydrogen peroxide and horseradish peroxidase (HRP). In the present study, urea as an adduct of hydrogen peroxide for color development could be omitted from the measurement solution. The measurement solution containing 5 mM hydrogen peroxide was deeply colored at a high absorbance value calculated as 46.7 cm−1 and was directly applied to the SPRAbs biosensing without dilution. The measurement was simply performed by dropping the measurement solution onto the surface of the SPR sensor probe, and the SPRAbs biosensor response to hydrogen peroxide was obtained as a reflectivity change in the SPR spectrum. After investigation of the pH profiles in the SPRAbs biosensor probe, a linear calibration curve was obtained between 1.0 and 50 mM hydrogen peroxide (r = 0.991, six points, average of relative standard deviation; 0.152%, n = 3) with a detection limit of 0.5 mM. To examine the applicability of this SPRAbs biosensor probe, 20 mM glucose detection using glucose oxidase was also confirmed without influence of the refractive index in the measurement solution. Thus, the SPRAbs biosensor probe employing the modified Trinder's reagent demonstrated applicability to other analyte biosensing tools.